1. Field of the Invention
The present invention relates to a stop device that abuts against a work during conveyance and stops the work.
2. Description of the Related Art
There is known a stop device that stops, at a predetermined position, a work conveyed on a conveyance device such as a roller conveyor. The stop device stops a work or cancels the stop by advancing, onto the conveyance device, an abutment portion such as a roller that abuts against a work, or retracting the abutment portion from the conveyance device. In order to relax a shock when a work abuts against the abutment portion, there is proposed a stop device in which the abutment portion is pivotally arranged and a mechanism for biasing the abutment portion to the upstream side is arranged (International Publication No. 2012/127867 and Japanese Patent Laid-Open No. 11-227937). The abutment portion pivots to a stop position from a position on the upstream side slightly from the stop position.
In some cases, a conveyance form is employed, in which a work is stopped, then is raised and processed, and is lowered again to a stop position.
However, when the work is raised, the abutment portion is pivoted to a position on the upstream side slightly from the stop position by the biasing force of a biasing mechanism. Since the abutment portion that stops a work is not located at the stop position upon lowering the work again to the stop position, the work may not be stopped and be conveyed.